1. Field of the Invention
The present invention relates to a device for use in a digital information processing electronic apparatus such as an electronic calculator combined with clock or a camera and for informing the user thereof of the replacing time of the battery.
2. Description of the Prior Art
The clock-combined electronic calculators which have recently become popular in the market employ CMOS large-scale integrated circuit elements for the processing unit and field-effect type liquid crystal elements for the display unit to achieve a low power consumption. Such apparatus working on very small batteries such as button-type silver oxide cell or coin-type lithium cell generally require battery replacement only once a year. Also there is becoming known an air-zinc battery which has a service life of two years or longer in a same size as that of the abovementioned batteries.
It is therefore required for a user to maintain a memorandum on the date of replacement, species and capacity of the replaced battery and estimated service life thereof and to thereafter replace the battery according to such data as otherwise the apparatus suddenly becomes unusable because of the battery run-out, thus causing significant inconvenience and uneasiness to the user.